Skip to main content

Anchor bolts

There are two main types of rotary vane steering gear in use today. One has its stator firmly fixed to the steering flat deck and the stator housing and cover are provided with suitable bearings to enable the unit to act as a combined rudder carrier and rudder stock bearing support. The other type of vane gear is supported where the stator is only anchored to the ships structure to resist torque but is free to move vertically within the constraints of the separate rudder head bearing and carrier which is similar to the bearing provided for ram type steering gears.
The rudder carrier ring bearing (Pallister Bearing) is taking the weight of the rotary vane steering gear and the rudder and stock.

 Rotation of the stator is prevented by means of two anchor brackets and two anchor bolts . The anchor brackets are securely bolted to the stool and vertical clearance is arranged between the inside of the Stator flanges and the top and bottom of the anchor brackets to allow for vertical movement of the rudder stock. This clearance varies with each size of rotary unit but could be about 40 mm total . It is essential that the rudder carrier should be capable of restricting the vertical movements of the rudder stock to less than this amount.


The anchor bolts are fitted with special bushes in halves, shaped externally in order to pre-load the synthetic rubber shock absorbers , which are fitted between them and the anchor brackets. The maximum deflection of the shock absorbers under full load is approximately 1 mm.



Comments

Popular posts from this blog

Differences between MC/MC-C and ME/ME-C engines

The electrohydraulic control mechanisms of the ME engine replace the following components of the conventional MC engine: Chain drive for camshaft Camshaft with fuel cams, exhaust cams and indicator cams Fuel pump actuating gear, including roller guides and reversing mechanism Conventional fuel pressure booster and VIT system Exhaust valve actuating gear and roller guides Engine driven starting air distributor Electronic governor with actuator Regulating shaft Engine side control console Mechanical cylinder lubricators. The Engine Control System of the ME engine comprises: Control units Hydraulic power supply unit Hydraulic cylinder units, including: Electronically controlled fuel injection, and Electronically controlled exhaust valve activation Electronically controlled starting air valves Electronically controlled auxiliary blowers Integrated electronic governor functions Tacho system Electronically controlled Alpha lubricators

Why is a man hole door elliptical in shape?

Any opening in a pressure vessel is kept to a minimum and for a man entry an elliptical hole  is lesser in size than the corresponding circular hole. More over it is prime concern to have a  smoothed generous radius at the corners to eliminate stress concentration. Hence other  geometrical shapes like rectangle and square are ruled out.  To compensate for the loss of material in the shell due to opening, a doubler ring has to be  provided around the opening. The thickness of the ring depends on the axis length along the  dirrection in which the stresses are maximum and the thickness of the shell. It is important to  align the minor axis along the length of the vessel, as the stress in this direction is  maximum. Longitudinal stress: Pd/2t where P= pressure inside the vessel, d= diameter of the arc, t=  thickness of the shell plating  Circumferential stress: Pd/4t  More over a considerable material and weight saving is achieved as minor is along the  direction of maximum stress.

Main engine interlocks

Interlocks are provided so that the engine can be started or reversed only when certain conditions have been fulfilled. When there is a remote control of engines, it is essential to have interlocks. This reduces the possibility of engine damage and any hazards to the operating personnel. Turning gear Interlock . This device prevents the engine from being started if the Turning gear is engaged. Running Direction Interlock . This prevents the fuel from being supplied if the running direction of the engine does not match the Telegraph. Starting Air Distributor in end position . This prevents starting from taking place if the shifting of the Distributor has not been completed. Main Lube. oil pressure, Piston cooling pressure, Jacket water pressure, and important parameters must be above the required minimum. Auxiliary Blower Interlock . The Auxiliary Blower is provided in case of Constant pressure turbo charging. Air Spring pressure Interlock . In case of the present generation